Background: Hypertrophic cardiomyopathy (HCM) is a complex myocardial disorder with heterogeneous clinical presentations and structural manifestations. This study aimed to assess the distribution, clinical characteristics, and diagnostic approaches in a regional cohort of patients with HCM.

Methods: Patients diagnosed with HCM at a tertiary cardiomyopathy clinic between October 2021 and November 2024 were retrospectively analyzed. Patients were classified into obstructive, latent obstructive, non-obstructive, or apical phenotypes based on clinical and imaging findings. Comprehensive demographic, clinical, and imaging data were collected for detailed analysis, providing valuable insights into the phenotypic diversity of HCM.

Results: The cohort included 701 patients with a median age of 53 years of whom 68% were male. The phenotypic distribution comprised 9.3% apical, 38.1% non-obstructive, 32.5% resting obstructive, and 20.1% latent obstructive HCM. Implantable cardioverter-defibrillator implantation was more common in obstructive phenotypes, particularly in the latent obstructive group. Although late gadolinium enhancement (LGE) was more frequently observed in apical HCM, post-hoc analysis showed no significant difference in prevalence across subgroups. In contrast, LGE extent was significantly greater in the apical group. Genetic testing, performed in 32% of patients, revealed a 44% positivity rate, with MYBPC3 and MYH7 being the most commonly detected mutations. The overall mortality rate was 2.8%, with heart failure identified as the leading cause of death.

Conclusion: In this large regional cohort of HCM patients, obstructive and non-obstructive phenotypes were predominant, with a notable burden of genetic mutations and a low overall mortality rate primarily driven by heart failure. These findings emphasize the clinical heterogeneity of HCM and highlight the importance of comprehensive diagnostic evaluation.